ARTICLE Breeding behavior, distribution, and conservation of the Sharp-tailed Tyrant Culicivora caudacuta (Vieillot, 1818) (Aves: Tyrannidae), a South American grassland specialist Robson Silva e Silva¹ ¹ Independent Researcher. Santos, SP, Brasil. ORCID: http://orcid.org/0000-0002-4086-7106. E-mail:
[email protected] Abstract. Culicivora caudacuta occurs in the Cerrado, Pampa and Chaco grasslands of Bolivia, Brazil, Paraguay, Argentina and Uruguay. Its breeding biology is poorly known. Here, I present a summary of the published information and new data gathered between 2003 and 2009 in southeast Brazil at Tapira, Minas Gerais. Breeding occurred during the rainy season (October to March), clutch size being three eggs. Juveniles and immatures show a different plumage from the adults, mostly brownish orange. All nests studied at Tapira showed evidence of cooperative breeding, with one helper engaged in incubation and provisioning the young. This is the first observations of this behavior for the species. The species has a wider range than currently understood and its presence in protected areas is similarly more common. Keywords. Nest description; Cooperative breeding; Eggs; Young plumage; Records. INTRODUCTION There are few studies of its biology and breed- ing behavior, the first data being gathered in The Sharp-tailed Tyrant Culicivora caudacuta Argentina in the early 20th century (Hartert & (Fig. 1) is a small tyrant flycatcher (Tyrannidae: Venturi, 1909), with little published since then. Elaeniinae) described in 1818 by Louis Jean Pierre Most of the available information refers to breed- Vieillot (1748-1830) as Muscicapa caudacuta (Le ing records and the presence of nests, young or Moucherolle a queue en aiguille), based on the immatures in the Brazilian states of Tocantins original description of the “Cola de agujas” (№ 277) (Dornas & Pascoal, 2019), Distrito Federal (Marini from Paraguay by Félix de Azara (1746-1821) et al., 2012), Goiás (Hass & Silva e Silva, 2008), (Vieillot, 1818).